Effect of human defensins on lactobacilli and liposomes
Article first published online: 12 SEP 2012
© 2012 The Society for Applied Microbiology
Journal of Applied Microbiology
Volume 113, Issue 6, pages 1491–1497, December 2012
How to Cite
Hugo, A.A., Tymczyszyn, E.E., Gómez-Zavaglia, A. and Pérez, P.F. (2012), Effect of human defensins on lactobacilli and liposomes. Journal of Applied Microbiology, 113: 1491–1497. doi: 10.1111/j.1365-2672.2012.05433.x
- Issue published online: 16 NOV 2012
- Article first published online: 12 SEP 2012
- Accepted manuscript online: 21 AUG 2012 06:29AM EST
- Manuscript Accepted: 14 AUG 2012
- Manuscript Revised: 13 JUL 2012
- Manuscript Received: 23 MAY 2012
- Agencia Nacional de Promoción Científica y Tecnológica. Grant Numbers: 0760/08, 145/08, 226/11
- Consejo Nacional de Investigaciones Científicas y Técnicas. Grant Number: 114-201101-0024
- Universidad Nacional de La Plata. Grant Number: X/574
To study the effect of human β-defensins (HBD-1 and HBD-2) on lactobacilli membranes as well as on liposomes prepared from purified bacterial lipids.
Methods and Results
Lactobacillus delbrueckii subsp. bulgaricus CIDCA 331 and Lact. delbrueckii subsp. lactis CIDCA 133 were grown in Man, Rogosa, Sharpe broth for 16 h at 37°C. After being washed, micro-organisms were treated with 0·1–10 μg ml−1 of HBD-1 and HBD-2 (30 min, 37°C). Bacterial damage was determined by flow cytometry after propidium iodide staining. In parallel experiments, release of carboxyfluorescein from liposomes prepared from bacterial lipids was determined fluorometrically (excitation 485/20 nm, emission 528/20 nm) in the presence of HBD-1, HBD-2 or Nisin. Exposure of lactobacilli to HBD-2 resulted in a significant membrane permeabilization being Lact. delbrueckii subsp. bulgaricus CIDCA 331 the most susceptible strain. Liposomes prepared with lipids from strain CIDCA 133 were destabilized neither by HBD-1 nor by HBD-2, whereas liposomes derived from strain CIDCA 331 were susceptible to HBD-2 but not to HBD-1. Effect of defensins was strongly inhibited in the presence of NaCl, and the activity increased in water.
Results reported in the presented work indicate that lipid composition of bacterial membranes lead to a different interaction with cationic peptides such as defensins.
Significance and Impact of the study
The results represent an advance in the understanding of the differential effect of HBDs on micro-organisms. Differences in susceptibility to anti-microbial peptides could modify the fate of micro-organisms after the interaction with host's cells.